NEC X551UN Series RS-232 / IP control commands

Summary

NEC X551UN Series professional projector supporting both RS-232C serial and wired LAN (TCP/IP) control. The serial interface uses RS-232C at configurable baud rates up to 115200 bps. The LAN interface uses TCP port 7142 for command transmission. Supports power control, input routing, picture/sound mute, lens positioning, and extensive status queries.

Transport

protocols:
  - serial
  - tcp
addressing:
  port: 7142  # stated for LAN/TCP control
serial:
  baud_rate: 115200  # highest rate listed; source lists 115200/38400/19200/9600/4800 bps as options
  data_bits: 8
  parity: none
  stop_bits: 1
  flow_control: none
auth:
  type: none  # inferred: no auth/login procedure described in source

Traits

- powerable       # power on/off commands present
- routable        # input switch command present
- queryable       # multiple status/information request commands present
- levelable       # volume, brightness, contrast, hue, sharpness, aspect adjustments present

Actions

- id: power_on
  label: Power On
  kind: action
  params: []

- id: power_off
  label: Power Off
  kind: action
  params: []

- id: input_sw_change
  label: Input Switch Change
  kind: action
  params:
    - name: input_terminal
      type: integer
      description: Input terminal hex code (e.g., 01h=COMPUTER, 06h=VIDEO, 20h=LAN)

- id: picture_mute_on
  label: Picture Mute On
  kind: action
  params: []

- id: picture_mute_off
  label: Picture Mute Off
  kind: action
  params: []

- id: sound_mute_on
  label: Sound Mute On
  kind: action
  params: []

- id: sound_mute_off
  label: Sound Mute Off
  kind: action
  params: []

- id: onscreen_mute_on
  label: Onscreen Mute On
  kind: action
  params: []

- id: onscreen_mute_off
  label: Onscreen Mute Off
  kind: action
  params: []

- id: picture_adjust
  label: Picture Adjust
  kind: action
  params:
    - name: target
      type: integer
      description: Adjustment target (00h=Brightness, 01h=Contrast, 02h=Color, 03h=Hue, 04h=Sharpness)
    - name: mode
      type: integer
      description: Adjustment mode (00h=absolute, 01h=relative)
    - name: value
      type: integer
      description: Adjustment value (16-bit signed)

- id: volume_adjust
  label: Volume Adjust
  kind: action
  params:
    - name: mode
      type: integer
      description: Adjustment mode (00h=absolute, 01h=relative)
    - name: value
      type: integer
      description: Adjustment value (16-bit signed)

- id: aspect_adjust
  label: Aspect Adjust
  kind: action
  params:
    - name: value
      type: integer
      description: Aspect mode hex code (see appendix for values)

- id: other_adjust
  label: Other Adjust (Lamp/Light)
  kind: action
  params:
    - name: target
      type: integer
      description: Adjustment target (96h=LAMP ADJUST / LIGHT ADJUST)
    - name: mode
      type: integer
      description: Adjustment mode (00h=absolute, 01h=relative)
    - name: value
      type: integer
      description: Adjustment value (16-bit signed)

- id: remote_key_code
  label: Remote Key Code
  kind: action
  params:
    - name: key_code
      type: integer
      description: Key code to send (see key code table for values)

- id: shutter_close
  label: Shutter Close
  kind: action
  params: []

- id: shutter_open
  label: Shutter Open
  kind: action
  params: []

- id: lens_control
  label: Lens Control
  kind: action
  params:
    - name: target
      type: integer
      description: Control target (06h=Periphery Focus)
    - name: direction
      type: integer
      description: Direction/mode (00h=Stop, 01h=+1s, 02h=+0.5s, 03h=+0.25s, 7Fh=+, 81h=-, FDh=-0.25s, FEh=-0.5s, FFh=-1s)

- id: lens_control_2
  label: Lens Control 2
  kind: action
  params:
    - name: control
      type: integer
      description: Control (FFh=Stop)
    - name: mode
      type: integer
      description: Adjustment mode (00h=absolute, 02h=relative)
    - name: value
      type: integer
      description: Adjustment value (16-bit)

- id: lens_memory_control
  label: Lens Memory Control
  kind: action
  params:
    - name: operation
      type: integer
      description: Operation (00h=MOVE, 01h=STORE, 02h=RESET)

- id: reference_lens_memory_control
  label: Reference Lens Memory Control
  kind: action
  params:
    - name: operation
      type: integer
      description: Operation (00h=MOVE, 01h=STORE, 02h=RESET)

- id: lens_memory_option_set
  label: Lens Memory Option Set
  kind: action
  params:
    - name: option
      type: integer
      description: Option (00h=LOAD BY SIGNAL, 01h=FORCED MUTE)
    - name: value
      type: integer
      description: Setting value (00h=OFF, 01h=ON)

- id: lens_profile_set
  label: Lens Profile Set
  kind: action
  params:
    - name: profile
      type: integer
      description: Profile number (00h=Profile 1, 01h=Profile 2)

- id: eco_mode_set
  label: Eco Mode Set
  kind: action
  params:
    - name: mode
      type: integer
      description: Eco mode hex code (see appendix for values)

- id: lan_projector_name_set
  label: LAN Projector Name Set
  kind: action
  params:
    - name: name
      type: string
      description: Projector name (up to 16 bytes, NUL-terminated)

- id: pip_picture_by_picture_set
  label: PIP/Picture by Picture Set
  kind: action
  params:
    - name: target
      type: integer
      description: Target (00h=MODE, 01h=START POSITION, 02h=SUB INPUT, 09h=SUB INPUT 2, 0Ah=SUB INPUT 3)
    - name: value
      type: integer
      description: Setting value (varies by target)

- id: edge_blending_mode_set
  label: Edge Blending Mode Set
  kind: action
  params:
    - name: mode
      type: integer
      description: Mode (00h=OFF, 01h=ON)

- id: freeze_control
  label: Freeze Control
  kind: action
  params:
    - name: state
      type: integer
      description: State (01h=ON, 02h=OFF)

- id: audio_select_set
  label: Audio Select Set
  kind: action
  params:
    - name: input_terminal
      type: integer
      description: Input terminal (see appendix for values)
    - name: value
      type: integer
      description: Audio source (00h=specified terminal, 02h=COMPUTER)
# Query (REQUEST) commands - all 25 documented in source

- id: error_status_request
  label: Error Status Request
  kind: query
  params: []

- id: information_request_cmd
  label: Information Request
  kind: query
  params: []

- id: filter_usage_info_request
  label: Filter Usage Information Request
  kind: query
  params: []

- id: lamp_info_request
  label: Lamp Information Request 3
  kind: query
  params:
    - name: lamp_number
      type: integer
      description: "Lamp number (00h=Lamp 1, 01h=Lamp 2)"

- id: carbon_savings_request
  label: Carbon Savings Information Request
  kind: query
  params:
    - name: type
      type: integer
      description: "Type (00h=Total, 01h=Operation)"

- id: lens_control_request_cmd
  label: Lens Control Request
  kind: query
  params:
    - name: target
      type: integer
      description: "Control target (06h=Periphery Focus)"

- id: lens_memory_option_request
  label: Lens Memory Option Request
  kind: query
  params:
    - name: option
      type: integer
      description: "Option (00h=LOAD BY SIGNAL, 01h=FORCED MUTE)"

- id: lens_information_request
  label: Lens Information Request
  kind: query
  params: []

- id: lens_profile_request
  label: Lens Profile Request
  kind: query
  params: []

- id: gain_parameter_request
  label: Gain Parameter Request 3
  kind: query
  params:
    - name: target
      type: integer
      description: "Adjustment target (00h=Brightness, 01h=Contrast, 02h=Color, 03h=Hue, 04h=Sharpness, 05h=Sharpness Detail, 96h=Lamp/Light)"

- id: setting_request
  label: Setting Request
  kind: query
  params: []

- id: running_status_request
  label: Running Status Request
  kind: query
  params: []

- id: input_status_request
  label: Input Status Request
  kind: query
  params: []

- id: mute_status_request
  label: Mute Status Request
  kind: query
  params: []

- id: model_name_request
  label: Model Name Request
  kind: query
  params: []

- id: cover_status_request
  label: Cover Status Request
  kind: query
  params: []

- id: information_string_request
  label: Information String Request
  kind: query
  params:
    - name: info_type
      type: integer
      description: "Type number (01h=Horizontal/Vertical sync freq)"

- id: eco_mode_request
  label: Eco Mode Request
  kind: query
  params: []

- id: projector_name_request
  label: LAN Projector Name Request
  kind: query
  params: []

- id: mac_address_request
  label: LAN MAC Address Status Request
  kind: query
  params: []

- id: pip_pbp_request
  label: PIP/Picture by Picture Request
  kind: query
  params: []

- id: edge_blending_mode_request
  label: Edge Blending Mode Request
  kind: query
  params: []

- id: base_model_type_request
  label: Base Model Type Request
  kind: query
  params: []

- id: serial_number_request
  label: Serial Number Request
  kind: query
  params: []

- id: basic_information_request
  label: Basic Information Request
  kind: query
  params: []

Feedbacks

- id: error_status
  label: Error Status
  type: object
  fields:
    - name: error_info
      type: object
      description: 12-byte error information bitmap (bit0=cover error, bit1=temp error, bit4=fan error, bit5=power error, bit6=lamp off, etc.)

- id: command_response
  label: Command Response
  type: object
  fields:
    - name: err1
      type: integer
      description: Error code high byte
    - name: err2
      type: integer
      description: Error code low byte
  # Error codes: 0000h=unrecognized, 0001h=unsupported, 0100h=invalid value, 0101h=invalid input, 0102h=invalid language, 0200h=memory alloc error, etc.

- id: running_status
  label: Running Status
  type: object
  fields:
    - name: power_status
      type: integer
      description: Power status (00h=Standby, 01h=Power on)
    - name: cooling_status
      type: integer
      description: Cooling status (00h=not executed, 01h=during execution)
    - name: operation_status
      type: integer
      description: Operation status (00h=Standby Sleep, 04h=Power on, 05h=Cooling, 06h=Standby error, 0Fh=Power saving, 10h=Network standby)

- id: input_status
  label: Input Status
  type: object
  fields:
    - name: signal_switch_status
      type: integer
      description: Signal switch process status
    - name: signal_list_number
      type: integer
      description: Signal list number (returned value is actual-1)
    - name: signal_type_1
      type: integer
      description: Selection signal type 1
    - name: signal_type_2
      type: integer
      description: Selection signal type 2 (01h=COMPUTER, 20h=DVI-D, 21h=HDMI, 22h=DisplayPort, etc.)
    - name: content_displayed
      type: integer
      description: Content displayed (00h=video, 01h=no signal, 02h=viewer, 03h=test pattern, 04h=LAN)

- id: mute_status
  label: Mute Status
  type: object
  fields:
    - name: picture_mute
      type: integer
      description: Picture mute (00h=Off, 01h=On)
    - name: sound_mute
      type: integer
      description: Sound mute (00h=Off, 01h=On)
    - name: onscreen_mute
      type: integer
      description: Onscreen mute (00h=Off, 01h=On)
    - name: forced_onscreen_mute
      type: integer
      description: Forced onscreen mute (00h=Off, 01h=On)

- id: model_name
  label: Model Name
  type: string
  description: Model name string (NUL-terminated)

- id: serial_number
  label: Serial Number
  type: string
  description: Serial number (NUL-terminated)

- id: cover_status
  label: Cover Status
  type: object
  fields:
    - name: status
      type: integer
      description: Cover status (00h=opened, 01h=closed)

- id: information_request
  label: Information Request
  type: object
  fields:
    - name: projector_name
      type: string
      description: Projector name (NUL-terminated, up to 49 bytes)
    - name: lamp_usage_time
      type: integer
      description: Lamp usage time in seconds
    - name: filter_usage_time
      type: integer
      description: Filter usage time in seconds

- id: filter_usage_info
  label: Filter Usage Information
  type: object
  fields:
    - name: filter_usage_time
      type: integer
      description: Filter usage time in seconds
    - name: filter_alarm_start_time
      type: integer
      description: Filter alarm start time in seconds (-1 if undefined)

- id: lamp_info
  label: Lamp Information
  type: object
  fields:
    - name: lamp_number
      type: integer
      description: Lamp number (00h=Lamp 1, 01h=Lamp 2)
    - name: content
      type: integer
      description: Content type (01h=usage time, 04h=remaining life)
    - name: value
      type: integer
      description: Lamp usage time in seconds or remaining life percentage

- id: carbon_savings
  label: Carbon Savings Information
  type: object
  fields:
    - name: type
      type: integer
      description: Type (00h=Total, 01h=Operation)
    - name: kilograms
      type: integer
      description: Carbon savings in kg (max 99999)
    - name: milligrams
      type: integer
      description: Additional mg (max 999999)

- id: gain_parameter
  label: Gain Parameter
  type: object
  fields:
    - name: status
      type: integer
      description: Adjustment status (00h=not possible, 01h=not possible, 02h=possible, FFh=not found)
    - name: upper_limit
      type: integer
      description: Upper limit (16-bit)
    - name: lower_limit
      type: integer
      description: Lower limit (16-bit)
    - name: default_value
      type: integer
      description: Default value (16-bit)
    - name: current_value
      type: integer
      description: Current value (16-bit)

- id: eco_mode
  label: Eco Mode
  type: integer
  description: Eco mode setting (see appendix for values)

- id: projector_name
  label: Projector Name (LAN)
  type: string
  description: Projector name via LAN (NUL-terminated, up to 17 chars)

- id: mac_address
  label: MAC Address
  type: string
  description: MAC address as hex string (e.g., 01h-23h-45h-67h-89h-ABh)

- id: pip_pbp_status
  label: PIP/Picture by Picture Status
  type: object
  fields:
    - name: mode
      type: integer
      description: PIP mode (00h=PIP, 01h=PICTURE BY PICTURE)
    - name: start_position
      type: integer
      description: Start position (00h=TOP-LEFT, 01h=TOP-RIGHT, 02h=BOTTOM-LEFT, 03h=BOTTOM-RIGHT)
    - name: sub_input_1
      type: integer
      description: Sub input setting
    - name: sub_input_2
      type: integer
      description: Sub input 2 setting
    - name: sub_input_3
      type: integer
      description: Sub input 3 setting

- id: edge_blending_mode
  label: Edge Blending Mode
  type: integer
  description: Edge blending setting (00h=OFF, 01h=ON)

- id: base_model_type
  label: Base Model Type
  type: object
  fields:
    - name: base_model_type_code
      type: string
      description: Base model type code
    - name: model_name
      type: string
      description: Model name (NUL-terminated)

- id: basic_information
  label: Basic Information
  type: object
  fields:
    - name: operation_status
      type: integer
      description: Operation status
    - name: content_displayed
      type: integer
      description: Content displayed
    - name: signal_type_1
      type: integer
      description: Signal type 1
    - name: signal_type_2
      type: integer
      description: Signal type 2
    - name: display_signal_type
      type: integer
      description: Display signal type
    - name: video_mute
      type: integer
      description: Video mute status
    - name: sound_mute
      type: integer
      description: Sound mute status
    - name: onscreen_mute
      type: integer
      description: Onscreen mute status
    - name: freeze_status
      type: integer
      description: Freeze status

- id: lens_control_request
  label: Lens Control Request
  type: object
  fields:
    - name: upper_limit
      type: integer
      description: Upper limit (16-bit)
    - name: lower_limit
      type: integer
      description: Lower limit (16-bit)
    - name: current_value
      type: integer
      description: Current value (16-bit)

- id: lens_memory_option
  label: Lens Memory Option
  type: object
  fields:
    - name: option
      type: integer
      description: Option (00h=LOAD BY SIGNAL, 01h=FORCED MUTE)
    - name: value
      type: integer
      description: Setting value (00h=OFF, 01h=ON)

- id: lens_information
  label: Lens Information
  type: object
  fields:
    - name: status_bits
      type: integer
      description: Lens status bitmap (bit0=lens memory, bit1=zoom, bit2=focus, bit3=lens shift H, bit4=lens shift V)

- id: lens_profile
  label: Lens Profile
  type: integer
  description: Selected profile number (00h=Profile 1, 01h=Profile 2)

- id: information_string
  label: Information String
  type: string
  description: Information string (horizontal/vertical sync frequency)

Variables

# UNRESOLVED: variables that are set/get via parameter commands are documented in Actions and Feedbacks
# The source does not clearly separate settable parameters from one-shot actions

Events

# UNRESOLVED: no unsolicited event/notification mechanism described in source
# The projector only responds to commands; no push-style events are documented

Macros

# No explicit multi-step macros are described in the source

Safety

confirmation_required_for:
  - power_off  # cooling time required; no other commands accepted during power off sequence
interlocks: []
# UNRESOLVED: power on/off commands have timing constraints (no other commands accepted
# during power transition/cooling) but no explicit safety interlock procedures stated
# UNRESOLVED: standby mode must be configured correctly for serial/LAN control to work
# Some models require specific standby modes (Normal, Active, Eco, Network Standby, Sleep, etc.)
# to receive POWER ON commands; supported modes vary by model

Notes

The X551UN Series supports a comprehensive command protocol over both RS-232C and TCP/IP. Serial configuration allows baud rates from 4800 to 115200 bps; the document prioritizes 115200 as the typical setting. LAN control uses TCP port 7142 exclusively.

Key command groups: power management (015/016), input selection (018), mute controls (020-025), picture adjustments (030-1 through 030-15), information queries (037 family), remote key emulation (050), lens/shutter control (051-053-11), status queries (078 family), eco mode (097-8/098-8), PIP/PBP (097-198/098-198), and edge blending (097-243-1/098-243-1).

Checksum calculation: sum all bytes preceding checksum, take low-order 8 bits. Control IDs (ID1, ID2) must match projector settings. Error responses use ERR1/ERR2 code pairs documented in section 2.4.

Provenance

source_domains:
  - sharpdisplays.eu
source_urls:
  - https://www.sharpdisplays.eu/p/download/cp/Products/Projectors/Shared/CommandLists/NEC-ExternalControlManual-english.pdf
retrieved_at: 2026-04-29T13:53:35.236Z
last_checked_at: 2026-06-02T22:12:32.952Z

Verification Summary

verdict: verified
checked_at: 2026-06-02T22:12:32.952Z
matched_actions: 53
action_count: 53
confidence: medium
summary: "All 53 spec actions traced to source (dip-safe re-verify). (6 unresolved item(s) noted in Known Gaps.)"

Known Gaps

- "model number exact variant (X551UN, X551UNS, etc.) not distinguished in source; UNRESOLVED: appendix supplementary tables referenced but not included (input terminal codes, aspect values, eco mode values, signal type values, audio select values)"
- "variables that are set/get via parameter commands are documented in Actions and Feedbacks"
- "no unsolicited event/notification mechanism described in source"
- "power on/off commands have timing constraints (no other commands accepted"
- "standby mode must be configured correctly for serial/LAN control to work"
- "appendix tables (input terminal codes, aspect values, eco mode values, signal type values, audio select values) are referenced but not included in the source document excerpt"

From the AI4AV catalog (https://ai4av.net) · ODbL-1.0

NEC X551UN Series Control Spec